Jointed control platform

ABSTRACT

A medical device having a force transmission mechanism that includes a chassis having a pivotal support that defines a first axis. An axle is supported by the pivotal support and is free to rotate around the first axis of rotation. The axle defines a second axis of rotation perpendicular to the first axis of rotation. A first control arm is coupled to a first end of the axle and is free to rotate around the second axis of rotation. A second control arm is coupled to an opposite second end of the axle and is free to rotate around the second axis of rotation independently of the first control arm. A distal component is coupled to an elongate tube that is coupled to the chassis. Four drive elements coupled to the control arms control motion of the distal component. In one implementation, the medical device is a teleoperated surgical instrument.

CROSS-REFERENCE TO RELATED APPLICATIONS

This patent application is a continuation of U.S. application Ser. No.16/269,159 (filed Feb. 6, 2019) (entitled “JOINTED CONTROL PLATFORM”),which claims priority to and the filing date benefit of U.S. ProvisionalPatent Application No. 62/628,133 (filed Feb. 8, 2018) (entitled“JOINTED CONTROL PLATFORM”), each of which is incorporated herein byreference in its entirety.

FIELD

Embodiments of the invention relate to the field of mechanical couplers;and more specifically, to a mechanical coupler for transferring motionfrom a teleoperated actuator to an attached surgical instrument.

BACKGROUND

Minimally invasive medical techniques have been used to reduce theamount of extraneous tissue which may be damaged during diagnostic orsurgical procedures, thereby reducing patient recovery time, discomfort,and deleterious side effects. Traditional forms of minimally invasivesurgery include endoscopy. One of the more common forms of endoscopy islaparoscopy, which is minimally invasive inspection or surgery withinthe abdominal cavity. In traditional laparoscopic surgery, a patient'sabdominal cavity is insufflated with gas, and cannula sleeves are passedthrough small (approximately 12 mm) incisions in the musculature of thepatient's abdomen to provide entry ports through which laparoscopicsurgical instruments can be passed in a sealed fashion.

The laparoscopic surgical instruments generally include a laparoscopefor viewing the surgical field and surgical instruments having endeffectors. Typical surgical end effectors include clamps, graspers,scissors, staplers, and needle holders, for example. The surgicalinstruments are similar to those used in conventional (open) surgery,except that the working end or end effector of each surgical instrumentis separated from its handle by an approximately 30 cm. long extensiontube, for example, so as to permit the operator to introduce the endeffector to the surgical site and to control movement of the endeffector relative to the surgical site from outside a patient's body.

In order to provide improved control of the working tools, it may bedesirable to control the surgical instrument with teleoperatedactuators. The surgeon may operate controls on a console to indirectlymanipulate the instrument that is connected to the teleoperatedactuators. The surgical instrument is detachably coupled to theteleoperated actuators so that the surgical instrument can be separatelysterilized and selected for use as needed instrument for the surgicalprocedure to be performed. The surgical instrument may be changed duringthe course of a surgery.

It will be appreciated that it is desirable to minimize the diameter ofthe extension tube, which couples the end effector to the teleoperatedactuators, to minimize the size of the incision necessary to introducethe surgical instrument to the surgical site. Teleoperated surgicalinstruments may have cables or bands that transfer the motion of theteleoperated actuators from a proximal control mechanism at a proximalend of the extension tube to the end effector at a distal end of thetube. The cables or bands may form a loop with two proximal ends in theproximal control mechanism. One proximal end may be pulled to apply aforce to the end effector while the other proximal end is payed out tomaintain an appropriate tension in the loop.

Rotary actuators, such as electric motors, are an effective way toprovide controlled actuation forces to a teleoperated surgicalinstrument. The proximal control mechanism translates the rotary inputforce into the push-pull motions of the two proximal ends needed tocontrol the end effector. The proximal control mechanism may receivemany such rotary inputs, perhaps four to eight, each of which can betranslated into an appropriate motion for controlling some aspect of theend effector. It is desirable that the proximal control mechanism becompact to avoiding crowding in the surgical field.

In view of the above, it would be desirable to provide an improvedapparatus and method for transmitting actuating forces to cables orbands intended for use in teleoperated minimally invasive surgeries.

SUMMARY

A force transmission mechanism includes a chassis having a pivotalsupport that defines a first axis of rotation. An axle is supported bythe pivotal support and is free to rotate around the first axis ofrotation. The axle defines a second axis of rotation perpendicular tothe first axis of rotation. A first control arm is coupled to a firstend of the axle and is free to rotate around the second axis ofrotation. A second control arm is coupled to an opposite second end ofthe axle and is free to rotate around the second axis of rotationindependently of the first control arm. An end effector is coupled to anelongate tube that is coupled to the chassis. Four drive elementscoupled to the control arms control motions of the end effector.

Other features and advantages of the present invention will be apparentfrom the accompanying drawings and from the detailed description thatfollows below.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention may best be understood by referring to the followingdescription and accompanying drawings that are used to illustrateembodiments of the invention by way of example and not limitation. Inthe drawings, in which like reference numerals indicate similarelements:

FIG. 1 is a view of an illustrative manipulating system of ateleoperated surgical system.

FIG. 2 is a side view of a surgical instrument for use with ateleoperated actuator.

FIG. 3 is a schematic representation of an embodiment of a forcetransmission that can be used to control an end effector of a surgicalinstrument.

FIG. 4 is a schematic representation of another embodiment of a forcetransmission.

FIG. 5 is a schematic representation of yet another embodiment of aforce transmission.

FIG. 6 is a schematic representation of a mechanism for moving the forcetransmission shown in FIGS. 3, 4, and 5 .

FIG. 7 is a schematic representation of another mechanism for moving theforce transmission shown in FIGS. 3, 4, and 5 .

FIG. 8 is a pictorial view of a partial assembly of an implementation ofthe force transmission shown schematically in FIG. 7 .

FIG. 9 is a pictorial view of another partial assembly of theimplementation of the force transmission shown schematically in FIG. 7 .

FIG. 10 is a pictorial view of the implementation of the forcetransmission shown schematically in FIG. 7 .

FIG. 11 is a pictorial view of the implementation of the forcetransmission shown schematically in FIG. 7 in another operativeposition.

FIG. 12 is an illustration of an end effector demonstrating anapplication of the force transmission.

FIG. 13 is an illustration of the end effector of FIG. 12 in anotheroperative position.

FIG. 14 is a side view of the end effector of FIG. 12 .

FIG. 15 is a side view of the end effector of FIG. 12 in yet anotheroperative position.

DESCRIPTION OF EMBODIMENTS

In the following description, numerous specific details are set forth.However, it is understood that embodiments of the invention may bepracticed without these specific details. In other instances, well-knowncircuits, structures, and techniques have not been shown in detail inorder not to obscure the understanding of this description.

In the following description, reference is made to the accompanyingdrawings, which illustrate several embodiments of the present invention.It is understood that other embodiments may be utilized, and mechanicalcompositional, structural, electrical, and operational changes may bemade without departing from the spirit and scope of the presentdisclosure. The following detailed description is not to be taken in alimiting sense, and the scope of the embodiments of the presentinvention is defined only by the claims of the issued patent.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting of the invention.Spatially relative terms, such as “beneath”, “below”, “lower”, “above”,“upper”, and the like may be used herein for ease of description todescribe one element's or feature's relationship to another element(s)or feature(s) as illustrated in the figures. It will be understood thatthe spatially relative terms are intended to encompass differentorientations of the device in use or operation in addition to theorientation depicted in the figures. For example, if the device in thefigures is turned over, elements described as “below” or “beneath” otherelements or features would then be oriented “above” the other elementsor features. Thus, the exemplary term “below” can encompass both anorientation of above and below. The device may be otherwise oriented(e.g., rotated 90 degrees or at other orientations) and the spatiallyrelative descriptors used herein interpreted accordingly.

As used herein, the singular forms “a,” “an,” and “the” are intended toinclude the plural forms as well, unless the context indicatesotherwise. It will be further understood that the terms “comprises”and/or “comprising” specify the presence of stated features, steps,operations, elements, and/or components, but do not preclude thepresence or addition of one or more other features, steps, operations,elements, components, and/or groups thereof.

The terms “or” and “and/or” as used herein are to be interpreted asinclusive, meaning any one item in a group or any combination of itemsin the group. Therefore, “A, B, or C” or “A, B, and/or C” mean “any ofthe following: A; B; C; A and B; A and C; B and C; A, B and C.” Anexception to this definition will occur only when a combination ofelements, functions, steps or acts are in some way inherently mutuallyexclusive.

The term “object” generally refers to a component or group ofcomponents. For example, an object may refer to either a pocket or aboss of a disk within the specification or claims. Throughout thespecification and claims, the terms “object,” “component,” “portion,”“part,” and “piece” are used interchangeably.

The terms “instrument” and “surgical instrument” are used herein todescribe a medical device configured to be inserted into a patient'sbody and used to carry out surgical or diagnostic procedures. Thesurgical instrument typically includes an end effector associated withone or more surgical tasks, such as a forceps, a needle driver, ashears, a bipolar cauterizer, a tissue stabilizer or retractor, a clipapplier, an anastomosis device, an imaging device (e.g., an endoscope orultrasound probe), and the like. Some instruments used with embodimentsof the invention further provide an articulated support (sometimesreferred to as a “wrist”) for the surgical end effector so that theposition and orientation of the surgical end effector can be manipulatedwith one or more mechanical degrees of freedom in relation to theinstrument's shaft or chassis. Further, many surgical end effectorsinclude one or more functional mechanical degrees of freedom, such asone or more jaws that open or close, or a knife that translates along apath.

FIG. 1 shows a pictorial view of a portion of a minimally invasiveteleoperated surgical system. The portion shown is placed adjacent asurgical patient 122 to support the surgical instruments and provideteleoperated actuators that control the surgical instruments. Thisportion of the teleoperated surgical system may be termed a manipulatingsystem 100. Typically, three or four surgical instruments 120, includinga camera instrument that provides images of the surgical site and otherinstruments at the surgical site, are supported by the manipulatingsystem 100. It will be appreciated that a minimally invasiveteleoperated surgical system uses a substantial amount of equipmentlocated in a small amount of space adjacent the surgical patient 122.While the manipulating system 100 is shown as providing four surgicalinstrument manipulators 130, other numbers of surgical instrumentmanipulators may be provided, such as one, two, three, or more thanfour. In some configurations, the teleoperated surgical system mayinclude more than one manipulating system. Examples of manipulatingsystems are included in the da Vinci® Surgical System Models IS1200,IS2000, IS3000, and IS4000 commercialized by Intuitive Surgical, Inc.,Sunnyvale, Calif. Manipulating systems include various ways in whichthey may be mechanically grounded, such as a cart that rolls on thefloor, a ceiling mount, a patient operating table mount, and the like.An example of how a manipulating system may be combined with theoperating table are the manipulators and manipulator positioning armsused for the Zeus® Surgical System commercialized by Computer Motion,Inc. and shown, for example, in U.S. Pat. No. 6,728,599 B2 (filed Sep.7, 2001).

In practice, a manipulator 130 may move the surgical instrument 120 as awhole, and it may also transmit force to the instrument to move one ormore instrument components, such as a wrist or jaw mentioned above. Inthe example shown, the teleoperated surgical instruments 120 are eachcoupled to a corresponding instrument carriage on a manipulator 130. Theinstrument carriage houses the teleoperated actuators that provide themechanical power that is transmitted to the instrument. In someconfigurations, the teleoperated actuators are housed elsewhere in themanipulator or in a supporting arm. The teleoperated actuators allow asurgeon to manipulate the surgical instrument using a computer-operateduser control station (not shown) that provides computer-assistedteleoperation. These manipulations may include functions such aschanging the position and orientation of the surgical instrument's endeffector and operating the end effector, such as closing jaws to effectgrasping, cutting, etc. Such actuator control of surgical instrumentsmay be referred to by various terms, such as teleoperated surgery. Eachmanipulator 130 may be supported on a separate structural arm 110 that,once positioned, can be fixed relative to the surgical patient 122. Invarious implementations the supporting arm 110 may be manuallypositioned, may be positioned via teleoperation by the surgeon, or maybe automatically positioned by the system as the surgeon moves one ormore of the surgical instruments 120.

A control system couples the computer-assisted user control station tothe teleoperated actuators. Here “computer” broadly encompasses a dataprocessing unit that incorporates a memory and an additive or logicalfunction, such as an arithmetic logic unit, that is programmable toperform arithmetic or logical operations. The computer-assisted usercontrol station includes one or more hand-operated control input devicesthat allow manipulation of the teleoperated slave surgical instruments120 by transmitting signals, such as electrical or optical controlsignals, to the actuators that control the actions of the coupledteleoperated surgical instruments. In this way a master-slaverelationship is established between the control input device of the usercontrol station and the surgical instrument of the manipulating system.

The hand-operated control input devices, and the images of the surgicalsite and instruments at the surgical site provided by a camerainstrument, may be arranged to provide an intuitive control of thesurgical instruments 120, in which the instruments move in a mannersimilar to the operator's hand movements with the controllers. Themovement of the surgical instruments 120 as displayed to the surgeon mayappear at least substantially connected to the control input devices inthe hands of the surgeon. Further levels of connection, such as force orother haptic feedback, may be provided to enhance the surgeon'sdexterity and ease of use of the surgical instruments 120. One, two,three, or more actuators may be provided to move the end effector of theassociated surgical instrument 120 with one or more mechanical degreesof freedom (e.g., all six Cartesian degrees of freedom, five or fewerCartesian degrees of freedom, jaw grip, etc.).

FIG. 2 is a side view of an illustrative embodiment of the surgicalinstrument 120, comprising a distal portion 250 and a proximal controlmechanism 240 coupled by an elongate tube 210. The distal portion 250 ofthe surgical instrument 120 may provide any of a variety of surgical endeffectors 254, such as the forceps shown, a needle driver, a cauterydevice, a surgical stapler, a cutting tool, an imaging device (e.g., anendoscope or ultrasound probe), or a combined device that includes acombination of two or more various tools and imaging devices. In theembodiment shown, the surgical end effector 254 is coupled to theelongate tube 210 by a wrist 252 that allows the orientation of thesurgical end effector to be manipulated with reference to the elongatetube 210. In addition, the tube 210 may rotate around its long axis sothat the end effector 254 correspondingly rolls around its long axis.The end effectors and the wrist illustrate various movable distalcomponents of the surgical instrument.

Surgical instruments that are used with the surgical invention maycontrol their end effectors, wrists, or any intervening jointed orflexible section with a plurality of any combination of drive elements,such as tension (pull) elements, compression (push) elements, orcombined tension/compression elements. Examples of these drive elementsinclude flexible cables and/or bands, push and/or pull rods,cable/hypotube combinations, Bowden cables, and the like, and they maybe made of materials such as steel, tungsten, or polymer (e.g., Dyneema®polyethylene). It will be appreciated that the drive elements should beinelastic and also as flexible as necessary so that pulling and/orpulling forces can be transmitted by the drive elements as they bendaround pulleys and guides.

A typical elongate tube 210 for a surgical instrument 120 is small,often in a range of five to eight millimeters in diameter, although theymay be larger (e.g., 14 mm) or smaller (e.g., 3 mm). The diminutivescale of the mechanisms in the surgical instrument 120 creates uniquemechanical conditions and issues with the construction of thesemechanisms that are unlike those found in similar mechanisms constructedat a larger scale, because forces and strengths of materials do notscale at the same rate as the size of the mechanisms. The drive elementsmust fit within the elongate tube 210 and be able to bend as they passthrough the wrist joint 252.

In a teleoperated surgical instrument, mechanical force originatingoutside the instrument (e.g., at a teleoperated actuator) must bereceived into the instrument and then directed to the instrumentcomponent to be moved (e.g., the instrument shaft, a wrist, an endeffector). Various mechanisms have been designed to carry this out. Forexample, force (the term “force” as used herein includes torque) may bereceived into the instrument via a rotating actuator output disk matedwith an instrument input disk, or via a moving actuator output lever orgimbal mated with an instrument input lever or gimbal, or via atranslating linear actuator drive mated with an instrument linear input.Once the drive force is received at the instrument, it is then directedto one or more drive elements by way of mechanisms inside theinstrument, such as capstans and cables, levers, gimbals, gears,pulleys, and the like.

FIG. 3 is a schematic representation of an embodiment of a jointedcontrol platform mechanism in a force transmission pathway inside aninstrument between proximal multiple force inputs and multiple driveelements in the instrument. As discussed above, these drive elements areused to control one or more distal components of the instrument, such asan end effector or wrist. Two control arms 310, 320 are shown. Eachcontrol arm 310, 320 has two control points, one control point at theopposite end of each arm. As shown, control point 316 is at one end ofarm 310, and control point 318 is at the opposite end of arm 310.Similarly, control point 326 is at one end of arm 320, and control point328 is at the opposite end of arm 320. As described in more detailbelow, a unique drive element is attached to a corresponding uniquecontrol point, so that each drive element is moved as the correspondingarm moves. Since there are four control points, four drive elements arecoupled to the combination of the two control arms. The drive elementsare then routed to the distal end of the instrument.

The two control arms 310, 320 are coupled together by an axle 300. Arm310 is coupled to one end of axle 300 between control points 316 and318, and arm 320 is coupled to the opposite end of axle 300 betweencontrol points 326 and 328. Arms 310 and 320 are each pivotally mountedto the axle 300 so that they independently rotate at the ends of axle300. Optionally arms 310 and 320 are mounted to opposite ends of axle300, and an axial roll joint (not shown) allows the opposite ends ofaxle to roll with respect to one another, thus allowing the arms torotate with respect to one another. The long axis 312 of axle 300defines a common axis of rotation for both arm 310 and 320, so that eacharm rotates about the common axis 312. Each control arm has onerotational degree of freedom with respect to the axle.

The axle 300 is pivotally supported to permit axle 300 to rotate aboutan axis 302 that is orthogonal to axis 312 and that extends in the samegeneral directions as arms 310 and 320. As shown, axis 312 is midwaybetween the ends of axle 300 at which arms 310, 320 are coupled. Axle300 has one rotational degree of freedom with respect to a ground planethat supports the axis of rotation 302 for the axle. It can be seen thatas axle 300 rotates 304 around axis 302, arm 310 moves closer to theground plane as arm 320 moves away from the ground plane, and viceversa. It can further be seen that each one of the control points 316,318, 326, 328 can be moved closer to or farther from the ground plane inone of two ways—by rotating 314, 324 an individual arm 310, 320 withreference to axis 312 of axle 300, or by rotating 304 axle 300 withreference to axis 302.

In the schematic of FIG. 3 , the four control points 316, 318, 326, 328are equally and symmetrically spaced such that the four control pointsare located at the vertices of a square when the four control points arecoplanar. Thus curvilinear translation in space (approximatelyperpendicular to the plane defined by axes 302 and 312) of one controlpoint on an arm will result in an equal curvilinear translation in spaceof its corresponding opposite control point on the arm as the armrotates about axis 312. Similarly, curvilinear translation in space(again, approximately perpendicular to the plane defined by axes 302 and312) of one control point on one control arm will result in an equalcurvilinear translation in space of its corresponding mirrored controlpoint, or its corresponding opposite control point, on the other arm asaxis 300 rotates about axis 302. Therefore, various combinations ofrotations around both axes 302 and 312 will result in translations ofthe four control points that in turn will result in various equaltranslations of drive elements attached at each control point. Equaltranslation of associated drive elements is required if a distalcomponent of the surgical instrument requires equal translation tooperate properly (e.g., equal and opposite cable pay-in and pay-out overa pulley, push rod translations to move a class 1 lever, and the like).

It can also be seen that the control points need not be at the physicalends of the levers, but may be at any location along the leversequidistant from axle 300 (axis 312) that provides the necessarygeometric relation between the four control points. And, the length ofaxle 300 between arms 310, 320 can likewise be varied to provide thenecessary geometric relation between the four control points. Thus whenthe control points are coplanar they can be at any positions along thearms 310, 320 and spaced apart by axle 300 to define any four-sidedpolygon necessary to provide the required displacement of the associateddrive elements as the arms 310, 320 rotate around axis 312 and the axlerotates around axis 302. It can further be seen that if the controlpoints are kept coplanar, then the mechanism functions as a two degreeof freedom gimbal, but when the control points are allowed to move offcoplanar alignment, many additional control point positions are possiblewhen compared to a normal gimbal. These observations also apply to thefollowing embodiments.

FIG. 4 is a schematic representation of another jointed control platformmechanism in a force transmission pathway inside an instrument betweenmultiple force inputs and multiple drive elements in the instrument. Themechanism illustrated by FIG. 4 is similar to the mechanism in FIG. 3 ,but one control arm 420 is longer than the other control arm 410. Eachcontrol arm 410, 420 is pivotally mounted to an axle 400 midway betweenthe control points 416, 418, 426, 428 on the control arm. When the fourcontrol points are coplanar, the four control points are located at thevertices of an isosceles trapezoid, in which the axle 400 forms a lineof symmetry for the trapezoid. It can be seen that although curvilineartranslations of the control points on each individual arm will be equalas the arm rotates 414, 424 around axis 412, curvilinear translations ofthe control points on the opposite arms will not be equal if the armsrotate through an equal angle around axis 412. In some instances,however, the individual arms may be rotated by different angles aroundaxis 412 so that equal curvilinear translation of one set of oppositecontrol points (416, 428 or 418, 426) occurs. If the arms 410, 420 areequidistant from axis 402 on axle 400, then as axle 400 rotates 404around axis 402 the curvilinear translations of the control points onone arm will be equal to the curvilinear translations of the controlpoints the other arm. If the arms 410, 420 are not equidistant from axis402 on axle 402, then as illustrated below curvilinear translations ofcontrol points of the two arms may or may not be equal, depending on thepositions along which each arm 410, 420 joins axle 400.

FIG. 5 is a schematic representation of another jointed control platformmechanism in a force transmission pathway inside an instrument betweenmultiple force inputs and multiple drive elements in the instrument. Themechanism illustrated by FIG. 5 is similar to the mechanism in FIG. 3 ,but each control arm 510, 520 is pivotally mounted to an axle 500 sothat the distances between the control points on the arm and the axle500 are not equal. Therefore, as an arm rotates 514, 524 around the axisof rotation 512 defined by axle 500, the curvilinear translation of theopposite control points on the arm is not equal. Optionally, or inaddition, the distances between the ends of the axle 500 and its axis ofrotation 502 are not equal. Therefore, as axle 500 rotates 504 aroundaxis 502, the curvilinear translations on the control arms will beunequal. It can be seen, however, that various combinations of rotationsof arms 510, 520 around axis 512 can result in equal curvilineartranslations of either mirrored or opposite pairs of control points onthe two arms. Likewise, various combinations of rotations or arms 510,520 around axis 512 and rotation of axle 500 around axis 502 can resultin equal curvilinear translations of two control points.

FIGS. 3 through 5 are intended to show some of the possible embodimentsof a mechanism that can be used to control a distal end component of asurgical instrument. Further variations are possible including, but notlimited to, mounting only one of the control arms so that the distancesbetween the control points and the axle are not equal or mounting one ormore control arms of differing lengths so that the distances between thecontrol points and the axle are not equal. Such variations may be madeto meet the requirements for controlling a particular distal endcomponent of a surgical instrument with various translations of theassociated drive elements.

FIGS. 6 and 7 are schematic representations of mechanisms in a forcetransmission pathway inside an instrument between multiple force inputsand multiple drive elements in the instrument. As described below, it ispossible to use three force inputs to control the four drive elementsand so not only reduce the overall complexity and cost of an instrument,but reduce the complexity and cost of the manipulator required tooperate the instrument with four independently controlled driveelements.

FIGS. 6 and 7 illustrate embodiments of force inputs to the mechanismsshown in FIGS. 3-5 . In general, various force input components may becoupled to the mechanisms illustrated in FIGS. 3-5 in order to eithermove the control arms individually or together as a unit. The forceinputs shown in FIGS. 6 and 7 are described with the use of levers, butother inputs such as cables, lead screw and nut combinations, cams, andthe like may be used. Levers provide a compact and robust way ofcontrolling axle 300 and arms 310, 320, as illustrated below. And,although class 1 levers are shown, class 2 and class 3 levers areoptionally used.

As shown in FIG. 6 , a class 1 lever 600 is coupled to the axle 300 torotate the axle around the axis 302 of its pivotal support asillustrated by the arrows 304 (see also FIG. 3 ). The lever 600 isillustrated as a class 1 lever with a fulcrum 606 between the forceinput coupling (resistance) point 602 at the axle and the force input(effort) point 604 for force applied to the lever from the instrumentmanipulator. The coupling between the lever 600 and the axle 300accommodates the changing distance between the coupling point 602, thefulcrum 606, and the axis 302 of the pivotal support of the axle, suchas a pin and slot combination or the like. Coupling point 602 is shownoutboard of arm 310, but optionally coupling point 602 is at anyposition between arm 320 and arm 310 sufficient to cause the requiredforce on the drive elements coupled to the control points as axle 300rotates around axis 302.

A second lever 610 is coupled to one of the control arms 310 to rotatecontrol arm around axis 312 at its pivotal coupling to the axle 300, asillustrated by the arrows 314. The coupling between the second lever 610and the control arm 310 accommodates the changing distance between theinput coupling (resistance) point 612, the fulcrum 616, and the axis 312of the pivotal support of the control arm, such as with a ball and slotcombination. Force input is applied at force input (effort) point 614.Input coupling point 612 is shown outboard of control point 316, butoptionally coupling point 612 is at any position between control point316 and control point 318 sufficient to cause the required force on thedrive elements coupled to the control points as arm 310 rotates aroundaxis 312.

A third lever 620 is similarly coupled to the other of the control arms320. As shown in FIG. 6 , third lever 620 is coupled to control arm 320in a similar manner to the way second lever 610 is coupled to controlarm 310. Lever 620 is coupled to arm 320 at input coupling (resistance)point 622, with fulcrum 626 and force input (effort) point 624 beingsimilar to fulcrum 616 and force input point 614 of second lever 610. Asshown, input coupling point 622 is on an opposite side of axis 312 frominput coupling point 612, but optionally it may be at any position onarm 320 as described above for coupling point 612 on arm 310.

It can be seen that on the condition that second lever 610 and thirdlever 620 do not move, then rotating axle 300 around axis 302 with thefirst lever 600 will also cause the control arms 310, 320 to rotatearound axis 312. And, the necessary dimensions being equal, therotations will be of equal magnitude. On the condition that lever 600does not move, then lever 610 controls rotation of arm 310 around axis312, and lever 620 controls rotation of arm 320 around axis 312, thesetwo rotations being independent. On the condition that lever 600 rotatesaxle 300 around axis 302, lever 610, lever 620, or both, may be moved tokeep one or more control points 316, 318, 326, and 328 at a desiredlocation in space, or to create various combinations of locations inspace for these control points that are used to control position ororientation of a distal end component of the instrument. Thus withvarious combinations of inputs (efforts) on the three levers, variouscombinations of curvilinear translations of the four control points andassociated drive elements may be obtained.

As shown in FIG. 7 , the second and third levers 710, 720 are coupled tothe control arms 310, 320 by extension arms 716, 726 so that thecoupling points 712, 722 lie on the axis of rotation 302 for the axle300 when the four control points 316, 318, 326, 328 are coplanar. Inthis position, rotating the axle 300 around axis 302 with the firstlever 700 causes both control points 316, 318 on control arm 310 to movewith respect to the two control points 326, 328 on control arm 320without rotating the control arms 310, 320 and moving the two controlpoints on each control arm with respect to one another. Thus, withcoupling points 712 and 722 positioned on axis 302, motion of lever 600moves the mechanism only around axis 302, and no rotations around axis312 occurs. Rotations of arms 310, 320 around axis 312 is carried out byrotating levers 710, 720 around their fulcrums 711, 721.

While FIGS. 6 and 7 show the use of levers coupled to the mechanismshown in FIG. 3 , it will be appreciated that levers can be similarlycoupled to the mechanisms shown in FIGS. 4 and 5 .

FIGS. 8 through 11 illustrate an implementation of the forcetransmission shown schematically in FIG. 7 that could be applied to theproximal control mechanism 240 of the surgical instrument 120 shown inFIG. 2 . FIGS. 8 and 9 show the mechanism with some parts removed toallow the remaining parts to be seen more clearly.

FIG. 8 is a pictorial view of a partial assembly of the implementationof the force transmission shown schematically in FIG. 7 . The proximalend of the elongate tube 210 is coupled to a base chassis 242 thatprovides the ground plane for the force transmission used to control theend effector 254 of the surgical instrument 120.

An axle 830 is supported by a pivotal support 832 having an axis ofrotation perpendicular to the midpoint of the longitudinal axis of theaxle. The pivotal support 832 is supported by a bracket 834 coupled tothe base chassis 242. The axle 830 thus has one degree of rotationalfreedom with respect to the ground of the base chassis 242.

A first lever 800 is coupled at a coupling point 802 to the axle 830 torotate the axle around the axis of rotation defined by pivotal support832. The first lever 800 is supported by a fulcrum 806 that is supportedby the base chassis 242, which provides a ground structure for theproximal control mechanism. The coupling between the lever 800 and theaxle 830 accommodates the changing distance between the coupling point802, the fulcrum 806, and the pivotal support 832 of the axle. As shown,this coupling 802 is a slot and pin. Effort is applied to the lever by ahigh pitch screw 808 and thread follower 804 with a tight tolerancebetween the screw and follower to minimize backlash for effectivecontrol.

FIG. 9 is a pictorial view of a partial assembly of the implementationof the force transmission shown schematically in FIG. 7 in which the twocontrol arms 910, 920 are shown. Control points 916 and 918 are onopposite ends of arm 910, and control points 926, 928 are on oppositeends of arm 920. Each control arm 910, 920 is pivotally mounted on theaxle 830 to permit rotation about a common axis defined by thelongitudinal axis of axle 830, such that each control arm has one degreeof rotational freedom and is otherwise constrained with respect to theaxle. Four drive elements (bands or cables; hidden from view underneatharms 910 and 920) are coupled to corresponding individual control points916, 918, 926, 928 and extend through bracket 834 and into tube 210.

As described above, second lever 810 is supported by a fulcrum 816 thatis supported by the base chassis 242. Each control arm 910, 920 includesan extension arm 921 (analogous to arms 716 and 726 in FIG. 7 ) so thatthe coupling point 922 between the control arm and the coupled leverlies on the axis of rotation for the pivotal support 832 of the axle 800when the four control points 916, 918, 926, 928 are coplanar. A ball andslot coupling is provided between the control arm and the coupled leverto provide a motion-accommodating coupling. A ball is shown on thecoupling point 922 of control arm 920. A slot 812 is shown in FIG. 8 onthe second lever 810 that will be coupled to a ball on control arm 910similar to the ball at coupling point 922 of control arm 920.

FIG. 10 is a pictorial view of the implementation of the forcetransmission shown schematically in FIG. 7 in which all componentsimplementing the schematic representation are shown. A third lever 820is supported by a fulcrum 826 that is supported by the base chassis 242.The third lever 820 is coupled to the coupling point 922 of control arm920 with a motion-accommodating coupling as described above. The thirdlever 820 couples a third lead screw 828 and thread follower 824 to thecontrol arms 920.

FIG. 11 is a pictorial view of the implementation of the forcetransmission shown schematically in FIG. 7 in which control arm 910 hasbeen rotated around axle 830 with respect to control arm 920. One of thelead screws 818 has been rotated to raise the thread follower 814 at theeffort end of the second lever 810. The second lever 810 is a class 1lever, and the resistance end, which is coupled to the control arm 910,causes the control arm to rotate about the supporting axle 830.

Thus as illustrated, three rotational inputs to the surgical instrumentare transformed to four individually-controllable drive elements in acompact, robust, and economical mechanism.

Other mechanisms may be used to move the axle and control arms of themechanisms shown schematically in FIGS. 3 through 5 in place of thelevers shown in FIGS. 6 through 11. For example, a lead screw and threadfollower may optionally be connected directly to the axle and/or controlarms of the force transmission or connected via other couplingmechanisms such as push rods. The axle and control arms may optionallyall be moved by the same type of mechanism or optionally a combinationof different types of mechanisms may be used. Rotational or linearactuators may be directly or indirectly coupled to the axle and controlarms.

FIGS. 12 through 15 illustrate an end effector 1200—a surgical shear isillustrated—to demonstrate how the mechanism may be used to control anend effector of a surgical instrument. The mechanism is not limited tocontrolling this type of end effector, or controlling the end effectorin the manner shown, or controlling an end effector. These figures aremerely to show an exemplary use of the force transmission as an aid tofurther understanding the mechanism's characteristics.

FIG. 12 shows the end effector 1200, which includes two jaws 1210, 1220coupled by a pivot 1202 such that each jaw can rotate independentlyabout the pivot. Each jaw is coupled to an associated pulley 1212, 1222.A corresponding drive element control loop, which may be formed from oneor more flexible cables and/or bands, passes over a pulley to rotate thepulley and the coupled jaw. The control loop may include non-flexibledrive element sections that couple flexible sections.

Two control loops may be used to control motions of the end effector.Each loop may independently control a motion of the end effector. Forexample, each loop may control the angular position (arbitrarily termed“yaw”) of one of two blades of a pair of shears. By coordinating themotions of the two loops, the blades of the shears can be opened andclosed with respect to one another. Both blades can also be moved in thesame direction (arbitrarily termed “pitch”) to position the shears at anangle that is offset from the longitudinal axis of the elongate tube.

Each control loop is moved by moving the two proximal ends 1214, 1216,1224, 1226 of the drive element loop. It will be appreciated that thepulley mechanism is a “length conserving” control mechanism in which themovement of one proximal end 1214, 1224 of the control loop is matchedby an equally sized movement of the other proximal end 1216, 1226 in theopposite direction. Coupling the two proximal ends of a control loop tothe two control points on a control arm that is pivotally coupled to anaxle at the midpoint between the two control points ensures that the“length conserving” requirement for movement of the control loop is met.That is, the loop does not go slack as the pulley rotates, and a forcecan be maintained in both parts of the loop between the pulley and thecontrol points in addition to the force on one side that is used torotate the pulley.

FIG. 13 shows the end effector 1200 of FIG. 12 after one end 1214 of thecontrol loop has been moved toward the proximal end of the surgicalinstrument by rotating the control arm and the other end 1216 of thecontrol loop has moved toward the distal end. This is a “lengthconserving” movement of the control loop created by rotation of asymmetrically pivoted control arm, as suggested by the arrows 1206, 1208on the control loop. The movement of the control loop causes the jaw1210 coupled to the pulley 1212 over which the control loop passes torotate, as suggested by the curved arrow 1204. The end effector may beused by rotating a single jaw as shown, by rotating both jaws inopposite directions, and by rotating both jaws in the same direction.The independent rotation of the two control arms of the forcetransmission provides the necessary movements of the ends of the controlloops for all these jaw rotations.

FIG. 14 shows a side view of the end effector 1200 of FIG. 12 . The endeffector 1200 is pivotally supported on a wrist pivot 1402 having anaxis that is perpendicular to an axis of the coupling pivot 1202 thatcouples the two jaws 1210, 1220. The axis of the wrist pivot 1402 isshown as intersecting the axis of the coupling pivot 1202 forsimplicity. However, the axis of the wrist pivot 1402 may be displacedfrom the axis of the coupling pivot 1202.

FIG. 15 shows the end effector 1200 after being rotated about the axisof the wrist pivot 1402 as suggested by the curved arrow 1504. Therotation about the axis of the wrist pivot 1402 shown is controlled bymoving both ends 1214, 1216 of the first loop in a distal direction, assuggested by the distally pointing arrow 1506, and moving both ends1224, 1226 of the second loop in a proximal direction, as suggested bythe proximally pointing arrow 1508. This needs to be a length conservingmovement, which can be provided by control arms that are coupled to anaxle that is pivotally supported at the midpoint between the two controlarms.

When the coupling points between the control arms and the coupled leverslie on the axis of rotation for the pivotal support of the axle, the endeffector 1200 can be rotated about the axis of the wrist pivot 1402without rotating the jaws about the coupling pivot 1202. But if thecoupling points do not lie on the axis of rotation for the pivotalsupport of the axle, it may be necessary to control the motion of thecontrol arms to avoid rotation of the control arms on the axle and theresulting rotation of the jaws.

While certain exemplary embodiments have been described and shown in theaccompanying drawings, it is to be understood that such embodiments aremerely illustrative of and not restrictive on the broad invention, andthat this invention is not limited to the specific constructions andarrangements shown and described, since various other modifications mayoccur to those of ordinary skill in the art. The description is thus tobe regarded as illustrative instead of limiting. For example, aspects ofthe mechanism shown and described may optionally be adapted for use in ateleoperated surgical instrument or in any other medical device machinein which independent control of four separate drive elements isrequired, such as in a teleoperated manipulator that is providing outputforces to an attached surgical instrument or in a hand-held device.Further, aspects of the mechanism may optionally have applicationsoutside of the medical device industry, such as in various robotic,teleoperated, and other technologies.

1-20. (canceled)
 21. A medical device comprising: a proximal mechanism,an elongate tube, a distal component, a first drive element, and asecond drive element; the distal component comprising a medical tool;the elongate tube having a first end coupled to the proximal mechanismand a second end opposite the first end, the second end coupled to thedistal component; the proximal mechanism comprising a pivotal support,an axle, and a control arm; the pivotal support defining a first axis ofrotation; the axle comprising a first end and a second end opposite thefirst end, a second axis of rotation being defined through the first endof the axle and the second end of the axle, the axle being supported bythe pivotal support so that the axle is free to rotate in the pivotalsupport around the first axis of rotation, and the second axis ofrotation is perpendicular to the first axis of rotation; a first controlpoint being defined on the control arm, and a second control point beingdefined on the control arm spaced apart from the first control point;the first end of the axle being coupled to the control arm between thefirst control point and the second control point, the control armrotatable around the second axis of rotation; the first drive elementbeing coupled between the first control point and the distal component;and the second drive element being coupled between the second controlpoint and the distal component.
 22. The medical device of claim 21,further comprising: a first drive input coupled to the axle at a firstdrive input coupling; and a second drive input coupled to the controlarm at a second drive input coupling, wherein the control arm and thesecond drive input rotate relative to one another around the first axisof rotation at the second drive input coupling.
 23. The medical deviceof claim 22, wherein: the first drive input comprises a first lever, andthe first drive input coupling comprises a first sliding coupling; andthe second drive input comprises a second lever, and the second driveinput coupling comprises a second sliding coupling.
 24. The medicaldevice of claim 21, wherein: the first drive element and the seconddrive element form a first loop with reference to a first moving part ofthe distal component.
 25. The medical device of claim 21, wherein: theaxle further comprises a first pin and a second pin opposite the firstpin; and the axle is supported by the pivotal support at the first pinand the second pin.
 26. The medical device of claim 21, wherein thecontrol arm is a first control arm, the medical device furthercomprising: a second control arm coupled to a second end of the axle,the first axis of rotation being equidistant from the first control armand the second control arm.
 27. The medical device of claim 26, whereinthe first control arm and the second control arm are the same length.28. The medical device of claim 26, further comprising: a third controlpoint and a fourth control point on the second control arm, the axlebeing between and spaced apart from the first, second, third, and fourthcontrol points.
 29. The medical device of claim 28, wherein the axle isequidistant from the first, second, third, and fourth control points.30. The medical device of claim 21, further comprising: a first levercoupled to the axle such that an effort applied to the first levercauses the axle to rotate about the first axis of rotation.
 31. Themedical device of claim 26, further comprising: a first lever and asecond lever, the first lever coupled to one of the first control armand the second control arm, and the second lever coupled to the otherone of the first control arm and the second control arm such that aneffort applied to one of the first lever and the second lever causes thecoupled control arm to rotate about the second axis of rotation.
 32. Amedical device comprising: means for pivotally supporting an axle thatdefines a first axis of rotation; means for rotating the axle around thefirst axis of rotation, the axle having a first end, a second endopposite the first end, and a second axis of rotation defined betweenthe first and second ends of the axle, the second axis of rotation beingperpendicular to the first axis of rotation; a first control arm coupledto the first end of the axle; a second control arm coupled to the secondend of the axle; means for rotating the first control arm around thesecond axis of rotation; and means for rotating the second control armaround the second axis of rotation independently of rotation of thefirst control arm.
 33. The medical device of claim 32, furthercomprising means for transferring motion of the first control arm andthe second control arm to an end effector.
 34. The medical device ofclaim 32, wherein the means for pivotally supporting the axle includes achassis, the medical device further comprising: an elongate tube havinga proximal end portion coupled to the chassis; and a medical toolcoupled to a distal end portion of the elongate tube.
 35. The medicaldevice of claim 34, further comprising: a first drive element coupled tothe first control arm, extending through the elongate tube, and coupledto the medical tool; a second drive element coupled to the secondcontrol arm, extending through the elongate tube, and coupled to themedical tool; and the rotation of the first control arm and the secondcontrol arm causing motion of the medical tool via the first driveelement and the second drive element.
 36. A medical device, comprising:a chassis pivotally supporting an axle, the chassis defining a firstaxis of rotation; an elongate tube having a proximal end portion coupledto the chassis; a medical tool coupled to a distal end portion of theelongate tube; a control arm coupled to the axle and configured torotate around the first axis of rotation, a lever coupled to the axle,the axle having a first end, a second end opposite the first end, and asecond axis of rotation defined between the first end of the axle andthe second end of the axle, the second axis of rotation beingperpendicular to the first axis of rotation; a lead screw coupled to thechassis and coupled to the lever, the lead screw configured to rotatethe lever, which causes the control arm to rotate around the second axisof rotation.
 37. The medical device of claim 36, further comprising: afirst control point defined on the control arm, and a second controlpoint defined on the control arm spaced apart from the first controlpoint, the first end of the axle being coupled to the control armbetween the first control point and the second control point.
 38. Themedical device of claim 36, wherein the control arm is a first controlarm, the medical device further comprising: a second control arm coupledto the axle and configured to rotate around the second axis of rotation,the lead screw configured to rotate the lever around the first axis ofrotation, which causes the second control arm to rotate around thesecond axis of rotation independently of rotation of the first controlarm.
 39. The medical device of claim 38, further comprising: a firstcontrol point defined on the first control arm, and a second controlpoint defined on the first control arm spaced apart from the firstcontrol point; a third control point defined on the second control arm,and a third control point defined on the second control arm spaced apartfrom the first control point; the first end of the axle being coupled tothe first control arm between the first control point and the secondcontrol point, and the second end of the axle being coupled to thesecond control arm between the third control point and the fourthcontrol point.
 40. The medical device of claim 36, further comprising: adrive element coupled to the control arm, extending through the elongatetube, and coupled to the medical tool, and rotation of the controlelement causes motion of the medical tool via the drive element.